An object of this invention is to provide an improved tooth brush construction which includes power means and power transmission means for rotating brush elements thereof,

Another object of this invention is to provide on a power driven tooth brush construction, which includes a handle portion for carry-ing motor means operable by batteries, also carried in the handle portion or by conventional current supply from usual outlets via suitable cord connection, and an arm portion removably mounted on the handle portion for carrying rotatable brush elements and power transmission means for interconnecting the brush elements and the motor means.

A further object of this invention is to provide an improved power driven tooth brush of the character described, with improved means for removably mounting interchangeable brush elements on the arm portion thereof.

Still another object of this invention is to provide an improved power driven tooth brush construction having belt-pulley power transmission means and access means to said transmission means for maintaining and adjusting the same.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

In the drawings, FIG. l is a side elevational view of a power driven tooth brush embodying the invention, with parts cut away and parts in section;

FIG. 2 is a top plan view thereof, with parts broken away;

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 1;

FIG. 5 is a sectional view taken on the line 5 5 of FIG. 1;

FIG. 6 is a sectional view taken on the line 6-6 of FIG. l;

FIG. 7 is a sectional view taken on the line 7-7 of FIG. 6;

FG. 8 is a side elevational view of one of the brush elements useful in the toothbrush embodying the invention;

FIG, 9 is a sectional view taken on the line 9-9 of FIG. 7;

FlG. 10 is a sectional view taken on the line 10-10 of FlG. 8.

The toothbrush of the instant invention comprises essentially a handle portion which carries an electric motor and a brush mounting arm portion which is removably mounted on the handle portion. Brush elements are removably and interchangeably mounted on the arm portion together with pulley-belt transmission means for interconnecting the brush elements and the motor means.

The handle casing 11, formed of molded plastic or the like, comprises opposed side walls 13, 14, a forward end wall 15, a rear end wall 16 and a bottom wall 17. The casing 11 is open at its top and is adapted to receive in the open end thereof, the rear end of arm casing 12.

3,242,516 Patented Mar. 29, 1966 The casing 12 is of rectangular hollow section, being formed of metal, plastic or the like, the same comprising a bottom wall 18, side walls 19, 20, a forward end wall 21, and a removable top plate 22, which seats on laterally related rabbeted edges 23 extending from side walls 19, 20. Plate 22 is held in place by screws 24 threaded into posts 25, 26 upstanding from bottom wall 1S.

The rear end wall 16 of casing 11 includes a forwardly projecting portion 27 at the upper end thereof, formed with a recess 28 having a curved bottom and a reentrant portion 29 at the top thereof, for receiving therein a tapered rear end portion 30 of casing 12. With the rear end 30 of casing 12 received in recess 28 and reentrant portion 29, the mid portion of said casing 12 will rest on the top edge of forward wall 15 of handle casing 11 and a bead 31 on the bottom wall 18 received in recess 32 on the top edge of wall 15 will restrain armcasing 12 against longitudinal movement relative to handle casing 11. Swivel latches 33 mounted on the forward ends of side walls 13, 14 are turned inwardly to engage lateral portions of the arm casing 12, to lock the same in place.

An electric motor 34 is mounted within handle portion 11, to be energized by batteries, not shown, which may be located within said handle portion, or alternatively, by cord means, not shown, for connection to the usual electrical outlets. The motor shaft 35 carries a conical drive gear 36, for the purpose hereinafter described.

The arm casing 12 has mounted thereon a pair of longitudinally spaced pulleys 37, 3S interconnected by an endless belt 39. The rear pulley 38 has its shaft extending to an opening in bottom wall 18 for separable coupling with a shaft 40 mounted within casing 11 and carrying conical gear 41 which meshes with drive gear 36.

The forward pulley 37 is adapted to drive a set of intermeshiug gears 42, 43, 44 disposed below bottom wall 18 at the forward end thereof and enclosed by said wall 18, side wall portions 45, 46 extending downwardly from side walls 19, 20 respectively, forward end wall portion 47 and rear end wall 48, and a slide plate 49 movably mounted in grooves formed by spaced ribs 50, 51 in the lower ends of side wall portions 45, 46.

The center gear 42 is driven from shaft 37a of pulley 37 xed thereto. Gears 43, 44 mesh with and are driven by gear 42. Each lof gears 42, 43, 44 is formed on its outer face with a central recess 52 of square section. Brush elements 53, 54, 55 are adapted to be removably mounted on said gears 42, 43, 44 respectively.

To this end, each of brush elements 53, 54, 55 includes a stub shaft 56 extending from the conical butt portion 57 of said elements. Shaft 56 .includes an annular portion 58 of reduced diameter immediately adjacent butt portion 57 and a projecting stub end 59 0f square section to be received in recess 52 of the associated gears 42, 43 or 44.

The plate 49 is formed with spaced keyhole slots 60 wherein the enlarged portion 61 thereof will pass the shaft 56 while the restricted portion 62 thereof Will just pass the shaft portion 5S. Thus, with plate 49 in a retracted position indicated in dot dash lines, FIG. 5, individual brush elements 53, 54, 55 may be removed or inserted into place `or interchanged, as desired. On moving plate 49 to the right, FIG. 5, to its normal position, the restricted portion 62 of slot 60 will receive shaft portions 58 of reduced diameter and brush elements 53, 54, 55 will be held in position for rotation and use. Detent means 63 on the underside of plate 49 at the side edges thereof and recesses 64, 65 on lower rib 5t), provide means for retaining plate 49 in either of its positions as described above.

The pulley shaft 37a is provided with a collar 66 to locate the same relative to wall 18. Top plate 22 is provided with bearing means 67 to receive the upper ends of the pulley shafts. Gears 43, 44 have bearing means 68 on the underside of wall 18.

It will be apparent, that motor 34 is effective to rotate brush element 53, through pulleys 37, 38, belt 39 and gear 42, while brush elements 54, 55 will be rotated through their gears 43, 44, meshing with gear 42.

Plate 22 may be readily removed from arm portion 12 by unscrewing screws 24, to expose the pulleys 37, 38 and belt 39 for repair, replacement or adjustment. The cup shaped brush elements 53, 54, 55 are particularly effective for cleaning the buccal (facial), lingual (palatal) and the occlusal surfaces of the teeth. Such brush elements will also massage and stimulate the gingival tissues.

The cone shaped brush element 70, FIG. 8 is adapted to clean the proximal surfaces of the teeth and to massage and stimulate the interproximal gingivae. Brush 70 is used singly and is attached to the central driven gear 42 as described above, leaving idler gears 43, 44 in meshing relation to gear 42 and free of attached brushes. A thin plate 72 mounted on shaft portion 58 lies in contact with the outer surface of plate 49 and covers the unused openings therein, as indicated in dotted lines in FIG. 5.

The arm portion 12 as a whole may be removed from handle portion 11, by pivoting swivel clips 33 outwardly to release said arm portion, and the same may the-n be lifted angularly away from handle portion 11, to expose the interior thereof for motor maintenance, battery replacement and the like.

As various changes might be made in the embodiment of the invention herein shown without departing from the spirit thereof, it is understood that all matter herein described or illustrated is not limiting except as set forth in the appended claims.

What is claimed is:

1. A motor driven toothbrush comprising a hollow handle casing with m-otor means mounted therein and an elongated hollow arm casing with the rear end thereof mounted on said handle casing, a plurality of intermeshing gear means on the forward end of said arm casing, a brush element mounted on each gear means, pulley belt means within said arm casing interconnecting said motor means and one of said gear means, whereby said one gear means is positively driven from said motor means and in turn drives the other gear means meshing therewith wherein each brush element includes shaft means having a projecting end removably engageable with an associated gear means, and retaining means movably mounted on said arm casing for retaining in one position thereof said brush elements in engaged relation to the associated gear means and when in another position thereof permitting each brush lelement to be disengaged from its associated gear means.

2. A toothbrush as in claim 1 wherein said retaining means comprises a plate formed with keyhole openings, each brush element including shaft means passable through the enlarged portion of said keyhole opening, said shaft means including a portion of reduced diameter passable through the reduced portion of said keyhole opening.

3. A toothbrush as in claim 1, wherein said handle and arm casings include coacting means at the rear ends thereof and latch means on the forward end of said handle casing engageable with mid portions of said arm casing for retaining said handle and arm casings in interengaged relation.

4. A toothbrush as in claim 1 wherein said arm casing includes a removable top plate for exposing the pulleybelt means for repair or replacement.

5. A toothbrush as in claim 1 wherein said pulley-belt means comprises a pair of longitudinally spaced pulleys mounted within said arm casing, belt means interconnecting said pulleys, conical gear means for connecting the rear pulley with said motor means, said rst mentioned gears means being connected to the forward pulley.